Cruise control fault

[guttley]

Hi, quick question, anybody know why my cruise control and gear shift warning would stop working after a short time until I restart the engine.
Thanks

[Paul-R]

Manual or automatic?

[guttley]

Manual

[Paul-R]

When you say stop working, in what manner? It would be engaged and then suddenly jump out? Refuse to engage when warm? Refuse after a certain length of time? Or what?

You really need to get the system read for error codes (DTCs) with a decent high end code reader, preferably Diagbox.

How many miles has it done? When was it last serviced?

[guttley]

It will work from start, i set it and all's fine then after about 20mins the displayed speed will change to -- and when you try to engage it again the 2 -- will just flash, its done 117000 miles and was last serviced just after Christmas, it does have a fault code that is linked to the stop start capacitor which I've yet to fix but wouldn't have thought it would cause the fault. The change gear warning will stop working at the same time as cruise control.

[Paul-R]

What diagnostic machine are you using? Diagbox or other high end diagnostic?

[Solarriors]

I also had the automatic cruise control failing while on the highway a few times and a restart would do. I don't know what trigger but I know after 4 times the error my belt exploded

[guttley]

It's a Autel Maxicom
It picked up 7 faults to start with but these were fixed with a new battery, alternator and power steering rack.
Hopefully not the belt, this was changed 2 years ago.

[Paul-R]

And there are definitely no new DTCs? My best guess is that it's something to do with the ABS, possibly a sensor.

[guttley]

Thanks, I'll get it checked out

[NotAnInterestingName]

I've had my DS5 for about 3 years. It's always self-cancelled its cruise control only when it's damp and the engine is cold. A few minutes later it works perfectly. Nothing recorded in Diagbox that seems to be related, I was wondering if it was damp in a sensor or connector.

Different symptoms but illustrating that these systems are complicated, with a myriad of assorted sensors and software.

Mine did it a lot less after I had it under-sealed, then it came back again. So I'm guessing the solvent displaced some water then it found its way back in. No idea really though.

The joys of French motoring.

[guttley]

I did wonder if it was damp related but dismissed that as it's been relatively dry these last few weeks. My first time with a French car, don't think I'll be in a rush to get another

[Solarriors]

French cars have quite sensitive parts, especially electronics because they cheap out a bit and use thin not hardened materials, but design, engineering and software wise they are solid. Basically, the execution is a bit frail in my experience with french cars